Dry sliding tribological behavior of AZ31-WC nano-composites

The present study investigates the effect of WC nano-particles on tribological behavior of magnesium based nanocomposites for varying wt% of WC (0.5, 1, 1.5 and 2 wt%). Nanocomposites are fabricated using ultrasonic vibration assisted stir casting method. Optical microscopy, scanning electron microscopy and energy dispersive x-ray patterns are used to characterize the base alloy and fabricated composites. Micro-hardness values of as-cast composites are obtained through Vicker's micro-hardness tester. Friction and wear behavior of fabricated composites are studied using pin-on-disk type tribotester at room temperature under dry sliding condition. Operating load range is 10–40 N while sliding speed range is 0.1–0.4 m/s. Characterization of Mg-composites confirms particle inclusion as well as better microstructural integrity with increase in reinforcement. Hardness value of composites increases with increase in the amount of WC nano-particles. Wear and friction behavior of base matrix are also enhanced due to incorporation of WC nano-particles. Different wear mechanisms occurring at the contact surfaces are ascertained through SEM images and EDAX patterns. Oxidation in the tested surface is also identified through SEM and EDAX. This yields better tribological behavior in composites. Keywords: Mg-WC nanocomposites, Ultrasonic vibration, Stir-casting, Wear, Friction